Composite bevel siding

ABSTRACT

A method is disclosed. The method includes forming a groove in at least one of opposing planar surfaces of a cellular thermoform plastic substrate. The groove is formed at an edge region of the substrate. A stiffener is positioned in the groove, and a fiber matt is laid on the at least one planar surface containing the groove. The stiffener and fiber matt are embedded in a thermoset resin. The thermoset resin is cured to form a fiber reinforced thermoset plastic reinforcement. The substrate is then cross-sectionally cut to form a profile. The profile can be further finished to form a beveled siding for buildings.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.11/797,982, filed May 9, 2007, now U.S. Pat. No. 7,665,262, which claimsthe benefit of priority under 35 U.S.C. §119(e) to U.S. ProvisionalApplication No. 60/798,740, filed May 9, 2006, the entire contents ofeach of these prior applications are incorporated herein by reference.

FIELD

The present disclosure relates to exterior siding for buildings. Moreparticularly, the present disclosure relates to beveled planks formedfrom the reinforced cellular plastic substrates and methods offabricating the planks. The planks can be substitutes for traditionalwood-based siding products.

BACKGROUND

In the discussion of the background that follows, reference is made tocertain structures and/or methods. However, the following referencesshould not be construed as an admission that these structures and/ormethods constitute prior art. Applicant expressly reserves the right todemonstrate that such structures and/or methods do not qualify as priorart.

As a replacement to traditional wood sidings, many new products havebeen developed. The primary focus of such products is weatherresistance. Also of considerable consideration are the overallauthenticity and other aesthetic qualities of the installed product on abuilding.

Two dominate products to consider are sidings made from fiber cement andvinyl. Fiber cement siding has an authentic look and feel when painted.It is a generally weather resistant material that is also thermallystable. However it has several undesirable characteristics. First, beinga cementitous material, it is heavy and difficult to work with usingcommon wood working tools and techniques. Also, due to manufacturinglimitations, this type of siding product is not available in atraditional beveled (or wedge shaped) geometry. What is meant by this isthat traditional siding products, whether a shake or clap board, arethicker at the bottom exposed butt end (+/−½″) and taper to a muchthinner thickness (+/−⅛″ or less) at the upper, overlapped edge. Currentfiber cement siding products are often thinner (+/−⅜″ or less) and donot vary in thickness across their width. The individual strips ofsiding are cut from a larger flat sheet. Rather than having across-sectional geometry that is a tapered wedge, it is produced as athin flat rectangle. In industry terminology, this is considered alapboard siding rather than true clapboard. A shortcoming of thisdifference in profile is the combined thickness created from overlappingtwo or more layers of siding when installed. Often the increasedthickness can causes issues with matching up with trim thicknesses. Thisis one consideration that prevents thicker more authentic profiles frombeing manufactured.

Vinyl siding provides a low maintenance cladding for certain end usersbut lacks an authentic appearance. Considerable efforts have been madeto enhance patterns and textures. In all cases however, the means ofattachment remains that the siding panels are interlocked with oneanother and “hung” loosely on the sidewall as opposed to being nailedfirmly into place. This leaves the siding susceptible to wind damage.Further the panels are installed in channels around window/door openingsand corners. In many instances, the water resistance along thisinterface relies on the house wrap or felt paper that covers thesheathing. Further, vinyl is flimsy and dimensionally unstable withrespect to temperature. As a result it is prone to buckle when exposedto high temperatures. Also limiting is the fact that each panel consistsof several courses of siding, and cannot be crafted or otherwisemodified on site to conform to a custom profile or exposure.

As an alternative, solid, cellular thermoform plastics, such as cellularpolyvinyl chloride, have the physical attributes to produce an authenticlook, feel, and workability. However, when considering long thingeometries such as is the case with siding products, they lack rigidityand thermal stability. Often, an exterior wall surface is not perfectlyflat and the siding material covering it must have the ability to remainstraight along long lengths to effectively conceal theseinconsistencies. Further, a siding material may experience a wide rangeof temperatures, especially when exposed to direct solar gains. Mostcommon plastics experience a considerable thermal coefficient of linearexpansion and contraction and also tend to soften, or become moreductile when heated, resulting in buckling. Without reinforcement, thesematerials typically do not possess adequate performance characteristicsto provide a product that has the desired rigidity and thermal stabilityneeded.

SUMMARY OF THE INVENTION

There is a need for a material that looks, feels and installs like atraditional wood siding product, but is comprised of a material being ofa wood-like consistency that can resist weather related concerns such aswarping, cupping, twisting, rot, insect damage, and paint delamination.The material needs to be rigid enough to remain relatively straightalong a span of 8-12′ and posses thermal characteristics to remain asstable (or more stable) as common wood species when exposed to variabletemperatures and moisture conditions.

Described herein is a composite siding material and method ofmanufacturing said siding. The composite siding consists of a substratematerial such as cellular polyvinyl chloride (CPVC) or other similarsubstrate and permanently attached reinforcement. The reinforcement isprovided by an embedded stiffening element(s) that is bonded to thesubstrate using low or medium viscosity thermoset plastic or permanentlycuring adhesive. The reinforcement provides improved rigidity andstability characteristics to the combination as compared to that of thesubstrate alone. A similar technique is described to create both aclapboard siding product and a shake siding product.

A substrate having the desired physical attributes is reinforced alongits backing. For example, the reinforcement may be a stiffener comprisedof (1) a continuous stiffening rib within the thicker bottom edge of theprofile, (2) a thin ply or fiber (matt or fabric) reinforced thermosetplastic laminated to the back of the profile or (3) a combination ofboth.

An exemplary embodiment of a plank comprises a cellular thermoformplastic substrate, a groove formed in at least one planar surface of thecellular thermoform plastic substrate, and a fiber reinforced thermosetplastic (FRP_(s)) backing on the at least one planar surface, theFRP_(s) backing including a fiber chord positioned in the groove, afiber matt placed upon at least a portion of the one planar surface, anda cured strip thermoset resin on the one planar surface in which thefiber chord and the fiber matt are embedded.

An exemplary embodiment of a plank comprises a cellular thermoformplastic substrate, having a groove formed in at least one planarsurface. It is to be understood that this groove is located along theback of the profile and may be of a simple rectangular geometry(commonly known as a dado groove), or one that prevents separation ofthe materials that are used to fill it as a result of the groovegeometry, as is the case with a “T” slot or flared bottom.

An adhesive or other curing resin can be used to fill a portion of thegroove void prior to placement of the stiffener. The stiffener can be(a) a single object such as a pre-made relatively long, narrow square orround cylinder. Such elements may be made of wood, cured fiberglass, orsimilar strong stable materials. Or (b) if a low enough viscosityadhesive or other curing resin is used, the stiffening element may be agrouping of generally long or continuous fibers (perhaps pre-saturated)such as a chord, pulled taught and arranged parallel to the length ofthe groove and plank. When compatible materials are used, the adhesive,once cured, will bond to the stiffener and permanently anchor it withinthe substrate profile. Excess adhesive that may overflow the filledgroove may simply be troweled smooth. The reinforcement aids in theoverall thermal and mechanical stability of the product and alsoprovides rigidity to long lengths of siding.

Another exemplary embodiment of a plank comprises a cellular thermoformplastic or similar substrate, having at least one planar surface abradedin effect creating an opened cell condition. The voids created alonggenerally the back surface are filled with a low viscosity adhesive oractivated thermoset resin. The low viscosity matrix also contains afiber matt or fabric that is placed over the surface. Once cured, thefiber reinforced backing is permanently attached and provides enhancedperformance characteristics to the plank. The lamination of resinsaturated matt aides in the overall thermal and mechanical stability ofthe product and reduces the risk of fracture when nailed.

A third exemplary embodiment of a plank comprises a cellular thermoformplastic substrate, having a groove formed in at least one planarsurface. This groove is located along the back of the profile and may beof a simple rectangular geometry, or one that prevents separation of thematerials that are used to fill it (as is the case with a “T” slot orflared bottom). The surface containing the groove is also abraded ineffect creating an opened cell condition. The groove and voids createdalong the back surface are filled with a low viscosity adhesive oractivated thermoset resin. The low viscosity matrix also contains bothfiber matt or fabric that is placed over the surface and a stiffeningrod like element placed in the groove. The fiber of the matt and the ribstiffener are contained within the same resin matrix, which is anchoredinto the surface of the substrate. Once cured, the reinforced backing ispermanently attached and provides enhanced performance characteristicsto the plank. In all cases, the curing resin is formulated to provide arigid, thermally stable reinforcement.

Once cured, the lamination of resin saturated matt aides in the overallthermal stability of the product, while the stiffener also providesrigidity to long lengths of siding.

An exemplary method of forming a siding product for a building comprisesforming a groove in at least one of opposing planar surfaces of asubstrate, the groove at an edge region of the substrate and thesubstrate formed from a cellular thermoform plastic, positioning a fiberchord in the groove, laying a fiber matt on the at least one planarsurface, embedding the fiber chord and fiber matt in a thermoset resinand curing the thermoset resin to form a FRP_(s) backing on the at leastone planar surface, and cross-sectionally cutting the substrate with theFRP_(s) backing to form a strip.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWING

The following detailed description can be read in connection with theaccompanying drawings in which like numerals designate like elements andin which:

FIG. 1 is a cross-section of an exemplary embodiment of a plank.

FIG. 2 is a cross-section of an exemplary embodiment of a plank with acoating of thermoset liquid resin on a first surface.

FIG. 3 is a cross-section of an exemplary embodiment of a plank with acoating of thermoset liquid resin on both a first surface and a secondsurface.

FIG. 4 is a cross-section of an exemplary embodiment of a plank with aFRP_(s) backing on both a first surface and a second surface that hasbeen cross-sectionally cut to produce exemplary embodiments of a taperedstrip.

FIG. 5 is a cross-section of an exemplary embodiment of plank that has a“T” slot cut into one of its surfaces.

FIG. 6 is a cross-section of an exemplary embodiment of a plank that hasa flared bottom slot cut into one of its surfaces.

FIG. 7 is a cross-section of an exemplary sheet illustrating locationsto be cut to form exemplary embodiments of planks.

FIG. 8 is a cross-section of an exemplary embodiment of a plank that hasbeen cross-sectionally cut to produce exemplary embodiments of a taperedstrip.

FIG. 9 is a schematic representation of an imitation wood grain patternin a surface of the substrate.

DETAILED DESCRIPTION

FIG. 1 is a cross-section of an exemplary embodiment of a plank 10 beingof arbitrary length. The plank 10 has a width 111, and thickness 110 andplanar surface 20 and 21. The width 111 is slightly larger (+/−½″) thanthe final siding profile and a thickness 110 is slightly greater (+/−⅛″)than the final siding profile. The additional material beyond the finalsiding profile is removed during a later finishing process. A pair ofgrooves 30 and 31 are formed into both planar surfaces of a coresubstrate 11 along opposing and opposite edges of each, by for example,common techniques such as milling. The grooves, having a depth ofapproximately one half the sheet thickness and a width of approximatelyhalf its depth, are set in from the edge. The core substrate 11 may be acellular thermoform plastic (i.e. cellular polyvinyl chloride) such asis manufactured by AZEK TRIMBOARDS™, or other similar material, that hasits outer planar surfaces abraded. The substrate being used can have anygeometric shape, such as a panel, a plank or a sheet.

FIG. 2 is a cross-section of an exemplary embodiment of a plank 10 withreinforcement applied on a first surface. FIG. 2 is a cross-section ofplank 10 being of arbitrary length, oriented horizontally, havingsurface 20 facing upwards. Fiber chord 40 is placed in groove 30. Fibermatt 41 is placed upon strip 11. Fiber chord 40 and matt 41 are embeddedin curing thermoset resin 42

The plank 10, having one of its planar surfaces 20 facing upwards, has acoating of thermoset liquid resin (i.e. a polyester blend) 42 applied. Achord or grouping of continuous fibers (such as fiberglass) 40 is placedinto the resin filled grove 30, then the entire surface 20 is coveredwith a strip of pressed fiber matt 41. The strip can be slightlynarrower than the plank width. The matt 41 is saturated with liquidthermoset resin and manipulated, e.g., rolled, to remove trapper air.The plank 10 is exposed to light radiation (or other means) to initiatethe curing of the activate thermoset resin. Once cured, the plank 10 isflipped over and the same process is repeated to the other side. FIG. 3is a cross-section of an exemplary embodiment of a plank 10 with aFRP_(s) backing 45 on both a first surface and a second surface.

After both sides are complete, the plank 10 is cut using common methods,such as a circular or band saw, to produce two tapered strips 12 and 13.FIG. 4 is a cross-section of an exemplary embodiment of a plank with aFRP_(s) backing 45 on both a first surface and a second surface that hasbeen cross-sectionally cut to produce exemplary embodiments of a beveledstrip. Typically, the plank 10 is cut diagonally, but othercross-sectional cutting paths can be used. These strips, slightly largerbut closely resembling the desired end profile, are then run through ashaper/molder having cutting blades of the final finished sidingprofile. Further, the strips 12, 13 can be the same dimensions, but canalso be of different dimensions and of different geometric shape.

An exemplary embodiment of a plank comprises a cellular thermoformplastic substrate, having a groove formed in at least one planarsurface. It is to be understood that this groove is located along theback of the profile and may be of a simple rectangular geometry. FIGS. 5and 6 each show a cross-section of an exemplary embodiment of plank 60that has a slot 62 cut into one of the surfaces of the substrate 64. Anexample of a slot 62 is a dado groove, or other groove that preventsseparation of the materials that are used to fill it as a result of thegroove geometry, as is the case with a “T” slot shown in FIG. 5 orflared bottom slot 70 as shown in FIG. 6. In the slot 62 is a stiffener66, as described herein, which is surrounded by an adhesive 68. Asillustrated in FIGS. 5 and 6, once the adhesive becomes solid, it iseffectively anchored into the substrate by means of its geometry.

An adhesive or other curing resin can be used to fill a portion of thegroove void prior to placement of the stiffening rib. The stiffener canbe (a) a single object such as a pre-made relatively long, narrow squareor round cylinder. Such elements may be made of wood, cured fiberglass,or similar strong stable materials. Or (b) if a low enough viscosityadhesive or other curing resin is used, the stiffening element may be agrouping of generally long or continuous fibers (perhaps pre-saturated)such as a chord, pulled taught and arranged parallel to the length ofthe groove and plank. When compatible materials are used, the adhesive,once cured, will bond to the stiffener and permanently anchor it withinthe substrate profile. Excess adhesive that may overflow the filledgroove may simply be troweled smooth. The reinforcement aids in theoverall thermal and mechanical stability of the product and alsoprovides rigidity to long lengths of siding.

Once installed, the FRP_(s) backing 45 can be concealed from view andthe machined surface of the strip can be the exposed surface. If a roughsurface is desired, such as is the case with many types of shakes; thesaw marks can be left on the surface. If a particular surface pattern isdesired, such as an imitation wood grain, the outward facingthermoplastic surface of the substrate, for example the surface of thecellular thermoform plastic substrate, can be heated and pressed on aform until cooled. The patterned thermoplastic can be the exposedsurface when installed. FIG. 9 is a schematic representation of animitation wood grain pattern in a surface of the substrate.

In an exemplary embodiment of the reinforcement with a concealedbacking, the backing is comprised of a thin ply of fiber (matt)reinforced thermoset plastic and a fiber (continuous) reinforced ribstiffener. The fiber of the matt and the rib stiffener are containedwithin the same resin matrix, which is anchored into the surface of thesubstrate. The curing resin is formulated to provide a rigid, thermallystable reinforcement

Several applications can be performed to produce a variety of paintgrade siding products and profiles from the strips. These products rangefrom individual shakes having a butt end thickness of ½″+/−⅛″, variablewidths of 4″-12″, and lengths of 12″-24″ and a rough surface, totraditional smooth finish clapboard siding having widths of 6″-8″ ormore and lengths of 12′ or more.

In some cases, such as for clapboard siding, there is a particularconsideration that allows for a more time and cost efficient method ofproducing large quantities of siding. It is the ability of creatingmultiple strips of siding from a larger single sheet. A sheet 55, asrepresented in FIG. 7, having a width that is three or more times thewidth of the finished clapboard profile, is modified so several boards50 similar to plank 10 of FIG. 3 can be produced by cutting at locations51. These boards 50 are then cut cross-sectionally to produce a pair ofsiding strips in the same manner as that which produced strips 12, 13.

When producing individual shakes, the resulting pieces are small (i.e.,about 4″-12″) in comparison to long lengths of clapboard siding (e.g.,often 8′ or greater). Further, they are installed with a gap betweeneach piece. There is less concern for expansion and contraction orrigidity of long lengths. As a result, the reinforcing rib stiffener maybe unnecessary. FIG. 8 is a cross-section of an exemplary embodiment ofa plank that has been cross-sectionally cut to produce exemplaryembodiments of a tapered strip 15. Rather than being left as a longlength of siding, strips 15 are cut into variable shake widths to matchthe specifications of the traditional product being replaced.

Although described in connection with preferred embodiments thereof, itwill be appreciated by those skilled in the art that additions,deletions, modifications, and substitutions not specifically describedmay be made without department from the spirit and scope of theinvention as defined in the appended claims.

1. A method comprising: forming a groove in at least one of opposingplanar surfaces of a substrate, the groove at an edge region of thesubstrate and the substrate formed from a cellular thermoform plastic;positioning a stiffener in the groove; laying a fiber matt on the atleast one planar surface; embedding the stiffener and fiber matt in athermoset resin and curing the thermoset resin to form a fiberreinforced thermoset plastic reinforcement; and cross-sectionallycutting the substrate with the fiber reinforced thermoset plasticreinforcement at an angle that is non-perpendicular to the at least oneplanar surface to form two profiles.
 2. The method of claim 1,comprising forming a pattern in a surface of the substrate.
 3. Themethod of claim 2, wherein the pattern is an imitation wood grain. 4.The method of claim 1, wherein the at least one opposing planar surfaceis at least partially abraded.
 5. The method of claim 4, wherein thethermoset resin embedding the stiffener and fiber matt is coated on theabraded surface.
 6. The method of claim 1, wherein the stiffener is afibrous material.
 7. The method of claim 6, wherein the fibrous materialis a fiber chord.
 8. The method of claim 1, wherein the stiffener is anelongated rod.
 9. The method of claim 1, further comprising the step ofrunning at least one of the profiles through a shaper/molder.
 10. Themethod of claim 1, wherein the cross-sectional cutting step forms twotapered profiles.
 11. A method comprising: forming a long sheet ofsubstrate having first and second opposing planar surfaces; forming aplurality of grooves for inserting stiffeners in the opposing planarsurfaces of the substrate, the substrate formed from a cellularthermoform plastic; positioning a stiffener in each of the groovesformed for inserting stiffeners; laying a fiber matt on each of theopposing planar surfaces such that each of the grooves containing astiffener is covered by the fiber matt; embedding the stiffeners and thefiber matt covering the grooves containing stiffeners on each of theopposing planar surfaces in a thermoset resin and curing the thermosetresin to form fiber reinforced thermoset plastic reinforcements; cuttingthe sheet into strips wherein each strip contains a groove in the firstopposing planar surface and a groove in the second opposing planarsurface, and wherein the distance between two grooves formed in a firstopposing planar surface of the substrate is substantially equal to thewidth of a strip; and cross-sectionally cutting each strip of the sheetwith the fiber reinforced thermoset plastic reinforcement to form twoprofiles from each strip.
 12. The method of claim 11, wherein a grooveformed in a first opposing planar surface of the substrate is spacedfrom adjacent grooves on the first planar surface a distancesubstantially equal to the width of the resulting profiles.
 13. Themethod of claim 11, wherein the cross-sectionally cutting step forms twoidentical profiles from each strip.
 14. The method of claim 11, whereineach of the strips cut from the sheet are identical.
 15. The method ofclaim 14, wherein each of the cross-sectionally cutting step foams twoidentical profiles from each strip.